I would like to be able to monitor a project I’m doing for Sustainable energy (where I will be monitoring the voltage input from a solar panel), and send myself an email if any of the components (the Arduino, the Xbee, the Real time clock, the sd card / shield) stops functioning properly

I thought using this code and the smtp library would send an email but I KEEP getting an error(see below), and I’m not quite sure why yet: